The installation of underground electrical power lines in cities is normally accomplished by passing one or more multiple conductor electrical cables through an insulating conduit suitably located beneath the ground. The foregoing type of installation is commonly required by codes or the like and above ground installations are also commonly placed in an insulating conduit even though each electrical cable includes electrical insulation thereabout.
With the advent of commercially available insulating conduits for electrical cables, there arose various problems of inserting or passing electrical cables therethrough and these problems have been compounded by the necessity, or at least the desire to pass as many cables as possible through each conduit. Normally, a light line, such as a cord or the like is extended through underground conduit as the conduit is placed in position in a trench or the like. Subsequently, a heavy wire, cable, or the like, is pulled through the conduit by the cord and then the wire or cable is attached in some manner to the end of an electrical cable having many conductors for pulling the electrical cable through the conduit. While this procedure is widely employed, it has been found that problems arise in connecting the pulling wire or line to a cable end and also, it is very difficult to pull a plurality of cables through a conduit, particularly, if they substantially fill the conduit. The pulling of large power cables through a conduit is normally accomplished with a power winch, as very considerable forces are required, because of the cable weight and possible resistance, if a tight fit occurs.
Despite the longstanding problems encountered in pulling large electrical cables through conduits, this operation is still carried out in substantially the same manner as was employed decades ago. Cable hangup during pulling and breaking of the connection between cable and draw line still occur with substantial loss of time and money, particularly by electrical power distribution companies. The present invention provides a simple but effective system for pulling large cables through conduits without the problems of the prior art.